This invention relates generally to a cleaning apparatus, and more particularly concerns a mounting device for a blade cleaner.
In the process of electrophotographic printing, a photoconductive surface is charged to a substantially uniform potential. The photoconductive surface is imagewise exposed to record an electrostatic latent image corresponding to the informational areas of an original document being reproduced. This records an electrostatic latent image on the photoconductive surface corresponding to the informational areas contained within the original document. Thereafter, a developer material is transported into contact with the electrostatic latent image. Toner particles are attracted from the carrier granules of the developer material onto the latent image. The resultant toner powder image is then transferred from the photoconductive surface to a sheet of support material and permanently affixed thereto.
This process is well known and useful for light lens copying from an original and printing applications from electronically generated or stored originals, and in ionography.
In a reproduction process of the type as described above, it is inevitable that some residual toner will remain on the photoconductive surface after the toner image has been transferred to the sheet of support material (e.g. paper). It has been found that with such a process that the forces holding some of the toner particles to the imaging surface are stronger than the transfer forces and, therefore, some of the particles remain on the surface after transfer of the toner image. In addition to the residual toner, other particles, such as paper debris (i.e. Kaolin, fibers, clay), (Hereinafter, the term "residual particles" encompasses residual toner and other residual particles remaining after image transfer.) The residual particles adhere firmly to the surface and must be removed prior to the next printing cycle to avoid its interfering with recording a new latent image thereon.
Various methods and apparatus may be used for removing residual particles from the photoconductive imaging surface. Hereinbefore, a cleaning brush, a cleaning web, and a cleaning blade have been used. Both cleaning brushes and cleaning webs operate by wiping the surface so as to affect transfer of the residual particles from the imaging surface thereon. After prolonged usage, however, both of these types of cleaning devices become contaminated with toner and must be replaced. This requires discarding the dirty cleaning devices. In high-speed machines this practice has proven not only to be wasteful but also expensive.
The shortcomings of the brush and web made way for another now prevalent form of cleaning known and disclosed in the art--blade cleaning. Blade cleaning involves a blade, normally made of a rubberlike material (e.g. polyurethane) which is dragged or wiped across the surface to remove the residual particles from the surface. Blade cleaning is a highly desirable method, compared to other methods, for removing residual particles due to its simple, inexpensive structure. However, mounting the blade for cleaning contact over a long span of a photoreceptor belt can be problematic.
It has been attempted in the past to mount blade cleaners such that a line tangent to the photoreceptor at the tip contact intersects the blade pivot point. This causes the moment created by the blade friction load to be zero and thus prevents any change in blade normal load due to the friction load. While this is usually fairly easy to accomplish on a drum photoreceptor or, on a belt photoreceptor near a corner roller (as in the Xerox 1065), it becomes difficult to locate the pivot point over a long span of flat belt photoreceptor in the photoreceptor tangent plane.
The following disclosures may be relevant to various aspects of the present invention and may be briefly summarized as follows:
U.S. Pat. No. 5,084,739 to Kalyandurg et al. discloses a cleaning apparatus which is loadable against a surface to be cleaned having a L-shaped self-loading blade, a holding member, and supporting members including a retaining pin and a spring member. The cleaning blade includes a base section and a cleaning section which can move relative to each other from unloaded positions to loaded positions.
U.S. Pat. No. 5,040,030 to Ziegelmuller discloses a cleaning blade for precise loading and sealing against an electrostatographic surface to be cleaned.